diff --git a/src/librustc_unicode/lib.rs b/src/librustc_unicode/lib.rs
index 467c9746900..79ce8aacae8 100644
--- a/src/librustc_unicode/lib.rs
+++ b/src/librustc_unicode/lib.rs
@@ -31,7 +31,7 @@
        html_root_url = "https://doc.rust-lang.org/nightly/",
        html_playground_url = "https://play.rust-lang.org/",
        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
-       test(no_crate_inject))]
+       test(no_crate_inject, attr(allow(unused_variables), deny(warnings))))]
 #![no_std]
 
 #![feature(core_char_ext)]
diff --git a/src/librustc_unicode/u_str.rs b/src/librustc_unicode/u_str.rs
index 2347cdebf22..57d96bf4371 100644
--- a/src/librustc_unicode/u_str.rs
+++ b/src/librustc_unicode/u_str.rs
@@ -190,6 +190,7 @@ impl<'a> Iterator for Utf16Items<'a> {
 ///
 /// ```
 /// #![feature(unicode, decode_utf16)]
+/// # #![allow(deprecated)]
 ///
 /// extern crate rustc_unicode;
 ///